Showing posts with label AdS/CFT. Show all posts
Showing posts with label AdS/CFT. Show all posts

Sunday, January 25, 2009

Voxels

A generalization of a voxel is the doxel, or dynamic voxel. This is used in the case of a 4D dataset, for example, an image sequence that represents 3D space together with another dimension such as time. In this way, an image could contain 100×100×100×100 doxels, which could be seen as a series of 100 frames of a 100×100×100 volume image. Although storage and manipulation of such data uses a lot of computer memory, this allows the study of spacetime systems.


There is a discussion over at Backreaction called, Conservative solutions to the black hole information problem It deals with a paper her and Lee Smolin wrote together.

Conservative solutions to the black hole information problem
By Sabine Hossenfelder and Lee Smolin
arXiv: 0901.3156,
Submitted on 20 Jan 2009) Abstract: We review the different options for resolution of the black hole loss of information problem. We classify them first into radical options, which require a quantum theory of gravity which has large deviations from semi-classical physics on macroscopic scales, such as non-locality or endowing horizons with special properties not seen in the semi-classical approximation, and conservative options, which do not need such help. Among the conservative options, we argue that restoring unitary evolution relies on elimination of singularities. We argue that this should hold also in the AdS/CFT correspondence.


It is important that one is set up in terms of progressing to the determination and explanation of the voxel in the context that Holography. Susskind uses it in the way one can interpret "the bit" of information.

A picture, a photograph, or a painting is not the real world that it depicts. It's flat, not full with three dimensional depth like the real thing. Look at it from the side-almost edge on. It doesn't look anything like the real scene view from a angle. In short it's two dimensional while the world is three dimensional. The artist, using perceptual sleight of hand, has conned you into producing a three dimensional image in your brain, but in fact the information just isn't there to form a three dimensional model of the scene. There is no way to tell if that figure is a distant giant or a close midget There is no way to tell if the figure is made of plaster or if it's filled with blood or guts. The brain is providing information that is not really present in the painted strokes on the canvas or the darken grains of silver on the photographic surface. The Cosmic Landscape by Leonard Susskind, page 337 and 338

Monday, February 13, 2006

Intersection of D Branes

I'm not going to try and kid you with "this stuff," as it is extremely beyond anything that any of us mere mortal can understand. So, if such a thought would be to simplify, then how would such thinking be attributed to such model building and make it easier for us lay people to comprehend where these people are working in terms of the way they do things.

What is important is that we can derive some method to this madness:) okay! rather this abstract thinking, to show some kind of similarity in lay people's current thought patterns for easy recognition.

I'll burn in hell, if I get this wrong, but surely from my "faulty trails (not Tower)" I can be forgiven, until a clearer picture is given to us, that I could revamp all that I said, and leave for you now, the trials and tibulation of a rogue what?:)

Now you have to think about what I am saying, if you understand indeed, that such a place exists in the picture below, which for us mortals to consider. Think for a minute about the blackhole and where I had been talking in relation to the collider, as well as, the cosmic collisions taking place, with higher energy particles in our own atmosphere.

Weak field manifestation has particle consideration evident, and we find these here on earth, as neutrinos. Do You see now?

Physicists Andrew Strominger and Cumrin Vafa, showed that this exact entropy formula can be derived microscopically (including the factor of 1/4) by counting the degeneracy of quantum states of configurations of strings and D-branes which correspond to black holes in string theory. This is compelling evidence that D-branes can provide a short distance weak coupling description of certain black holes! For example, the class of black holes studied by Strominger and Vafa are described by 5-branes, 1-branes and open strings traveling down the 1-brane all wrapped on a 5-dimensional torus, which gives an effective one dimensional object -- a black hole.


I thought this to be part of the trivial effort with which I had departed to the bulk perspective, without really undertanding how I had got there. Yet I do see in these ways and many things are encompassed within it(gravitonic concentration). I would say, like Clifford telling us about the proper way in which we should move within these mathematical environs, then I would say what a rogue scholar I make, becuase this seems be the bastard child I am whose school is by insight developement, and some of it, wrong of course. But I try.

Superstrings, black holes and gauge theories


D-branes are non-perturbative excitations of string theory on which open strings can end. Open strings have gauge fields, so the D-branes define a gauge theory. There is a class of black hole made of D-branes, and these have a quantum gauge theory description. The closed strings define a field theory of gravity.



PROSPECTS FROM STRINGS AND BRANESA.SEVRIN

Strings occur in two versions: closed and open strings. Roughly speaking, one has that closed strings carry the gravitational interaction and the open strings carry the gauge interactions. While closed strings can freely propagate in space, the modern point of view is that the end points of open strings are “stuck” on p-dimensional hypersurfaces, where p ∈ {1, 2, · · · , 9}. These hypersurfaces are known as Dp-branes. They are dynamical but they are extremely heavy in the perturbative regime of string theory (their tension or energy per unit of volume is inversely proportional to the string coupling constant): they are solitons. A D0-brane is a point-like object, a D1-brane a string-like object, a D2-brane a membrane, ... Just as a propagating point particle sweeps out a curve – the world-line – in space-time, a Dp-brane sweeps out a p + 1-dimensional volume – the world-volume – in the 10-dimensional space-time. The effective dynamics on the world-volume is then described by a p + 1-dimensional field theory.





D-branes represent a key theoretical tool in the understanding of strongly coupled superstring theory and M-theory. They have led to many striking discoveries, including the precise microphysics underlying the thermodynamic behaviour of certain black holes, and remarkable holographic dualities between large-N gauge theories and gravity. This book provides a self-contained introduction to the technology of D-branes, presenting the recent developments and ideas in a pedagogical manner. It is suitable for use as a textbook in graduate courses on modern string theory and theoretical particle physics, and will also be an indispensable reference for seasoned practitioners. The introductory material is developed by first starting with the main features of string theory needed to get rapidly to grips with D-branes, uncovering further aspects while actually working with D-branes. Many advanced applications are covered, with discussions of open problems which could form the basis for new avenues of research


The link below contains over 222 pages, so if you are on Dial-up, you have to think twice about clicking on it. Another of Cosmic Variance's very own.


D-Brane PrimerClifford V. Johnson
Following is a collection of lecture notes on D-branes, which may be used by the reader as preparation for applications to modern research applications such as: the AdS/CFT and other gauge theory/geometry correspondences, Matrix Theory and stringy non-commutative geometry, etc. In attempting to be reasonably self-contained, the notes start from classical point-particles and develop the subject logically (but selectively) through classical strings, quantisation, D-branes, supergravity, superstrings, string duality, including many detailed applications. Selected focus topics feature D-branes as probes of both spacetime and gauge geometry, highlighting the role of world-volume curvature and gauge couplings, with some non-Abelian cases. Other advanced topics which are discussed are the (presently) novel tools of research such as fractional branes, the enhancon mechanism, D(ielectric)-branes and the emergence of the fuzzy/non-commutative sphere.